1. Field of the Invention
The present invention relates to a radiation detector for detecting radiation such as X-rays, γ-rays, and the like.
2. Related Background Art
Conventionally, techniques for detecting radiation include an indirect conversion method and a direct conversion method. According to the indirect conversion method, radiation is once converted to light and said light is converted to an electrical signal, while according to the direct conversion method, radiation is directly converted to an electrical signal. Therefore, the direct conversion method has a feature that the resolution is higher than that of the indirect conversion method where the resolution can possibly be degraded by scattering of light. For this reason, in recent years, radiation detectors by the direct conversion method have been attracting attention.
As the radiation detector by the direct conversion method, known is one including a substrate, a signal readout substrate having a plurality of pixel electrodes arranged one-dimensionally or two-dimensionally on a front surface (a surface on the side where radiation is made incident) of said substrate, a photoconductive layer formed on a front surface of the signal readout substrate, and a common electrode formed on a front surface of the photoconductive layer (see Japanese Published Unexamined Patent Application No. 2003-209238, for example).